The present disclosure relates to a power relaying apparatus, a power transmission system including the power relaying apparatus and a method for manufacturing the power relaying apparatus. The power relaying apparatus is also referred to as a power relaying terminal or a repeater. To put it in more detail, the present disclosure relates to a technology for transmitting power in a non-contact way also referred to as a wireless way by applying a resonance technique.
There have been proposed a plurality of methods for transmitting power from a power supplying apparatus also referred to as a power transmitting terminal to a power receiving apparatus also referred to as a power receiving terminal in a non-contact way. A method for transmitting power in a non-contact way is also referred to as a non-contact power supplying method, a wireless power supplying method or a wireless power transmission method. The power transferred to an electronic apparatus serving as a power receiving apparatus on the power receiving side can be utilized as power used for driving the electronic apparatus. As an alternative, by configuring the power receiving apparatus to serve as a power accumulator, the power transferred to the electronic apparatus on the power receiving side in the wireless way can be used as power utilized for electrically charging a secondary battery employed in the electronic apparatus.
The principle of the non-contact power transmission makes use of electro-magnetic energy. The non-contact power transmission is categorized into two large categories, i.e., radiation transmission and non-radiation transmission. The radiation transmission is also referred to as electric-wave receiving or electric-wave harvesting. The radiation transmission is further categorized into microwave radiation transmission and laser radiation transmission. On the other hand, the non-radiation transmission is further categorized into electromagnetic induction non-radiation transmission and resonance non-radiation transmission also referred to as electromagnetic resonance non-radiation transmission. Nowadays, attention is paid to the resonance transmission making use of either of electric-field resonance and magnetic-field resonance which are advantageous as viewed from several modes including the efficiency, the transmission distance, the positional shift and the angular shift. In particular, attention is focused on a method referred to as a magnetic-field resonance method or a magnetic resonance method. The magnetic-field resonance method or the magnetic resonance method makes use of the magnetic-field resonance which is affected only a little bit by energy absorption by a biological body. That is to say, the magnetic-field resonance has a small dielectric-substance loss. For more information on the magnetic-field resonance method or the magnetic resonance method, the reader is advised to refer to PCT Patent Publication No. WO 2009-140506.
The resonance method is a method for transmitting power from a power supplying apparatus for supplying power to a power receiving apparatus for receiving power transmitted by the power supplying apparatus by making use of coupling based on resonance of an electric or magnetic field between a resonance device employed in the power supplying apparatus and a resonance device employed in the power receiving apparatus. In the following description, the resonance method making use of the resonance of an electric field is referred to as an electric-field resonance method whereas the resonance method making use of the resonance of a magnetic field is referred to as a magnetic-field resonance method.